Proliferative diabetic retinopathy happens when abnormal new blood vessels grow inside the eye, potentially leading to bleeding or retinal detachment, which can cause vision loss. The goal of treatment is to stop the growth of those blood vessels and prevent vision loss. Traditionally, ophthalmologists have used a laser to make tiny burns in the retina, which cause the abnormal blood vessels to shrink and prevent them from growing again.

Recently, ophthalmologists began using another method – injecting a medication directly in the eye. This approach, called anti-VEGF therapy, also helps stop the blood vessels from growing or leaking.

Both methods can control blood vessel growth and preserve vision. But researchers are now finding that there may be an important difference between these treatments. It appears that people treated with injections alone need to be treated regularly and perhaps indefinitely to maintain their vision. That means no skipped appointments. Ophthalmologists say the consequence for interrupting this treatment is steep: potential blindness.

Problem is, many people with diabetes don’t see their ophthalmologists as regularly as they should. Things happen: appointments are forgotten, other health issues crop up, financial problems happen. But missing appointments may be more devastating to your vision if you are treated with injections alone compared with laser treatment, which typically controls the disease permanently.

Two studies, conducted by ophthalmologists at Wills Eye Hospital and the University of Michigan Kellogg Eye Center, looked at people who didn’t return to their physician for four to six months. Of those patients, those receiving treatment with injections alone suffered significantly more vision loss than those receiving laser treatment. One study showed that nearly half the patients who had a major interruption in anti-VEGF therapy suffered severe and often irreversible vision loss.

“It is critical for patients to understand that anti-VEGF drugs disappear from the eye within a month or two and do not have a lasting effect in most cases,” said Mark W. Johnson, MD, professor of Ophthalmology at the University of Michigan. “Patients receiving this form of treatment for proliferative diabetic retinopathy must continue to receive injections on a regular basis. Otherwise, the disease may progress with sometimes blinding consequences. In contrast, the beneficial effect of adequate laser treatment lasts indefinitely in most eyes.”